1. Field of the Invention
The present invention relates to an improvement of a tool changer for a welding robot which is adapted to supply electricity, gas, air, water and the like to a tool such as a welding robot gun.
2. Description of the Prior Art
A tool changer for welding robot of this type is known as illustrated in FIG. 10. The prior tool changer for welding robot will be described hereunder with reference to FIG. 10. The prior tool changer for welding robot comprises a base 131 connected to a welding robot arm (not shown), an absorbing plate 133 supported by the substrate 131 via piano lines at three points thereof for absorbing a lateral displacement of movement of a holding plate 137, the holding plate 137 supported by the absorbing plate 133 via piano lines 134 at three points thereof for holding a guide pin 135 and a connector 136 (for supplying electricity, gas, air, water), and other substrate 138 provided with female portions 139, 140 respectively for receiving the guide pin 135 and the connector 136.
With the arrangement of the prior tool changer for welding robot the other substrate 138 is moved close to the substrate 131 so that the guide pin 135 is inserted into the female portion 139 whereby the connector 136 can be inserted into the female portion 140. Even if there is any displacement or positional error between the guide pin 135 and the connector 136 or between the female portions 139, 140, the displacement or positional error therebetween (lateral or oblique direction) can be absorbed by the piano lines whereby the connector can be connected in place.
However, there are following problems in the prior tool changer for welding robot.
(1) There are provided a plurality of piano lines at the base side, where the guide pin and the connector are provided, for absorbing the displacement or positional error and the like so that the construction thereof becomes complex with high cost in manufacturing thereof.
(2) Various connectors depending on the various purposes at the tool side are provided both at the side of the tool or the welding gun and the side of the robot arm whereby a considerable cost, and a facility to be involved in the provision thereof are required as well as laborious and inefficient replacement thereof.
(3) Furthermore, according to the tool changer for welding robot having the transformer at the side of the tool side the tool changer per se is bulky as a whole of the tool changer and is positioned high in the center of gravity thereof which causes the tool changer to be unstable.
It is therefore an object of the present invention to provide a tool changer for a welding robot provided with a displacement or a positional error absorbing unit at the female portion thereof to overcome the problem as set forth above (1), connectors unitized in plural numbers and detachably mounted on the base or the substrate to overcome the problem as set forth above (2), and a transformer centrally disposed between the connectors to overcome the problem as set forth above (3).
A tool changer for a welding robot comprises male portions of connectors provided at a substrate fixed to a robot arm side for supplying electricity, gas, air, and water to the tool side from the robot arm side; and female portions of connectors to be connected to the male portions of the connectors and provided at a substrate fixed to a tool side for receving electricity, gas, air, and water from the male portions of connectors, each female portion composed of the connector, a protective tube provided at the substrate fixed to the welding gun side, a coupler inserted inside thereof, and an O-ring provided between the protective tube and the coupler, wherein the connector and the coupler are integrally formed and are radially slidable within the protective tube around the O-ring.
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.